Elaborate on the reason(s) that matter is said to move even as in a solid state.

The matter does not move in solid state but vibrates.

Explanation:

The atoms inside the matter cannot move or shift their positions without any external force but makes some small vibration movements. Generally in solids, the particles are bound by the attractive forces acting in between the atoms inside the matter.

The small vibrations that are happening inside the matter are because of the external factors like temperature. The increase in temperature raises the kinetic energy of the atoms inside and makes them move faster and this results in the vibration of the matter.

a.

explanation:

at positions a, g kinetic energy is maximum.

at position d, potential energy is maximum.